If you only have one...go lifestealing
If you have two...lifestealing PvP MH / 15agi PvP OH
In PvE, I only DW if the mob is lvl15 and lower...regardless of your preference, based on proc to miss rating ratios, you should use the following chart:
PvE with +5 to boots:
SW:
mobs level 28 and lower use Unholy enchant
mobs level 29 and higher use Agility enchant
DW:
mobs level 18 and lower use Unholy enchant
mobs level 19 and higher use Agility enchant